Truing tool



R. G. SMITH TRUING TOOL Filed Jan. 13 1922 INVENTOR Patented Nov. 25, 1924:.

l lZlTEfi TATE ROBERT e. SMITH, or rnvrne'ron, new JERSEY.

TRUING TOOL.

Application filed January 13, 1922.

To all whom it may canoe m:

Be it known that I, ROBERT G. SMITH, a citizen of the United States, and resident of Irvington, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Truing Tools, of which the following is a specification.

The connecting rod crank pins of engines, and particularly of internal combustion engines, are liable to become uneven during wear, and it has been customary, so far as I am aware, to remove the crank shafts from the engines in order to true or turn the crank pins to desired diameter, which entails considerable expense incidental to removal and the replacement in the engine of such crank shafts.

The object of my invention is to provide a simple and efficient tool adapted to be applied upon the crank pins of engine shafts to be rotated thereon to restore such crank pins to their proper cylindrical condition without requiring the crank shafts to be removed from the engine, my engine also being applicable for truing shafts, rods, and the like in other machinery.

In carrying out my invention I provide a tool comprising opposing members provided with an opening therebetween to receive a crank pin or other part to be trued, the interior of said members at such opening being provided with cutters to engage the stock of the crank pins or the like to cut it, with means to retain said members in operative relation around the said stock, said tool having means to enable its rotation around the stock. The tool is also provided with means to retain its said members in rigid adjusted relation, according to the diameter of the crank pin, or the like, as the same is reduced in truing it.

My invention also comprises novel details of improvement, that will be more fully hereinafter set forth, and then pointed out in the claims.

Reference is to be had to the accompanying drawings, forming part hereof, wherein- Figure 1 is a perspective view illustrating my improvement upon the crank pin of a crank shaft;

Fig. 2 is a partly broken edge view, enlarged, of my improved tool;

Fig. 3 is a partly broken side view of Fig. 2;

Fig. 4 is a section on line 4, 1, of Fig. 3;

Serial No. 528,929.

Fig. 5 is a detail of a modification.

Similar numerals of reference indicate corresponding parts in the several views.

The numerals 1 and 2 indicate the main members of my improved tool, which are movably connected or hinged together near one side by means of hinge pin 3 so that said members may be spread apart to be clamped around a crank pin a or other stock to be trued. While the hinge and pin 3 may be of any suitable construction, I have shown member 2 provided with spaced jaws 5 receiving jaw 6 of member 1, through which jaws pin 5 is passed, and a screw 7 engages member 2 and pin 3 by means of a threaded hole partly in said member and partly in said pin, indicated at 8, whereby said pin is kept from rotating on member 2 and is retained in place. Members 1 and 2 are shown provided with opposing diametrically disposed faces 1 2 and with centrally disposed recesses 1 2 which recesses oppose, preferably in circular manner, to provide a central opening to receive pin or stock 4 therebetween. At the side of members 1 and 2, opposite the hinge pin 3, I provide means to lock and rigidly retain said members together for the cutting operation. For such purpose I have shown the member 2 pro-- vided with a cross pin 9 within a recess 10, on which pin the head 11 of a screw bolt 11 is hung, the free end of said screw bolt being adapted to enter a recess 12- in the periphery of member 1, the nut 13 of said screw bolt being operative in the inset portion 12 of recess 12 to retain the members 1, 2, in operating position. At 15 are screws carried by member 1, at opposite sides of recess 12 adapted to engage opposing surface of member 2, the slots or heads of said screws being adapted to be operated in the recessed part 12 for setting the screws 15 tightly against member 2 to retain the members 1, 2, in rigid adjusted position in cooperation with screw bolt 11 and nut 13. Instead of using screws 15 the bolt 11 may have an extra nut 13 to act with nut 13 against member 1 to retain the members 1, 2, set. At 16 are cutters projecting inwardly from the inner circumference of members 1, 2, into their respective recesses 1", 2 in position to engage the crank pin or work 4. Said cutters are shown in the form of elongated rectangular pieces having cutting edges 16 the cutters being received in transversely disposed recesses 17 in members 1, 2, I provide the members 1, 2, with dowel pins 18, set in holes in the bottoms of the recesses 17 and projecting into said recesses, adapted to receive centrally disposed holes 18 in the cutters 16 to insure proper position of said cutters in the members 1, 2. Screws 20 are carried by the members 1, 2, near opposite ends thereof, and on opposite sides of the dowel pins 18, to engage thread ed holes 16 in cutters 16. The n'ie-mbers 1, 2, are shown provided with holes for screws 20 having countersunk shoulders 21 to receive the heads of said screws when the latter are screwed into the cutters to draw the latter and securely retain them in their recesses in members 1, 2, seated rigidly against the bottoms of the recesses or against interposed shims 22 at the bottoms of said recesses. The shims are provided with holes to receive the dowel pins and the screws 20. The shims may be made of varying thickness so as to be interposed between the bottoms the recesses 17 and the adjacent faces of cut ters 16 to cause their cutting edges 16 to project more or less within the recesses 1", 2 of the tool, according to the diameter of the crank pin or stock 1 to be trued. The tool may be provided with a handle or other suitable means for rotating it. I have shown a handle or bar 23 adapted to be inserted in any one of the spaced holes 2 1 in the periphery of members 1, 2, for convenience in resetting the handle in the tool for rotation of the latter upon the crank pin or stock.

Where the stock, such as crank pins, has one or more fillets, indicated at 4", the outer edges 16 of the cutters 16 may be reduced orrounded to accommodate such fillets, so as not to cut the same. The cutters 16 are shown slightly longer than the width of members 1, 2, so that the sides of the latter will not engage the jaws 1 of the crank shaft. The peripheral edge portions 1 2 of the members 1, 2, are shown reduced below the periphery thereof, wherein the heads of screws 20 are counter-sunk.

When the tool is to be used the screw 11 is released and swung out from member 1, the cutters 16 are set in said members according to the diameter of crank pin or stock 4, members 1, 2, are placed around the crank pin or stock, said screw is returned to its position in member 1, and the nut 13 and screws 15 are adjusted to bring the cutters 16 into proper cutting relation to the crank pin or stock. The tool is then rotated around the stock to cut it. hen it is required to advance the cutters to the work, it may be done by slackening screws 15 and setting nut 13 as may be required, and resetting screws 15, and so on, until a certain depth of out has been made. During the rotation of the tool upon the crank pin or stock the latter will be trued by the cutters, the chips passing away through the open sides of the recesses 1 2 In case it is necessary to advance the cutters toward the work more than will be permitted by the adjustment of screws 15, the shims 22 may be replaced by thicker ones and the screws 20 set to draw the cutters 16 against such shims, the screws 11 and 15 being re-adjusted'to accord with such thicker shims and rotation of the tool upon the work will proceed as before stated.

My improved tool will accurately and expeditiously operate to true uneven crank pins and other round stock, and is particularly useful in truing crank pins of internal combustion engines, since the tool will operate upon such pins when the connecting rods have been released therefrom while the crank shaft remains in position in the engine. This has the advantage or reducing the cost of truing crank pins over the pre-' vious requirements to removethe crank shaft from the engine for such purpose.

Having now described my invention, what I claim is 1. A truing tool comprising opposing members having an opening therein, said members having transverse recesses communicating with said opening, cutters detachably carried transversely by said members in said recesses to project into said opening, means to detachably retain. said cutters in said members, said members being movably connected on one side and provided with detachable locking means on the other side, and screws on opposite sides of the locking means to cooperate with the members to adjust and retain said members in rigid set relation when held by the lockingmeans.

2. A truing tool comprising opposing members having an opening therein, said members having transverse recesses communicating with said opening, cutters detachably carried transversely by said members in said recesses to project into said opening, means to detachably retain said cutters in said members, said members being movably connected on one side, a screw bolt pivoted to the opposite side of one of the members, the other member having a peripheral recess to receive said bolt, a nut on the bolt cooperative with the last named member, one of said members having a screwv at one side of the plane of the screw bolt operative 

